Apparatus for photometrically analysing liquid samples

Abstract

An apparatus for photometrically analyzing liquid samples comprises a capsule (1) in which a measuring cell (7) is housed. This cell is inserted in a flow circuit for liquid samples delivered from containers (R) travelling on a conveyor (17). Each sample is taken up by a pivoting arm (15) and with the aid of a pump (13). The volume of the measuring cell (7) is so calculated that the quantity of liquid sample contained in the containers (R) is sufficient firstly to rinse the cell with this liquid then for the measurement to be carried out. A particular application is the measurement of bioluminescence reactions produced in samples containing living organisms.

We claim: 
     
       1. Apparatus for photometrically analysing successive liquid samples, which comprises measurement cell means disposed in a light-proof enclosure and adapted to successively receive liquid samples to be analyzed, photometric detector means in said enclosure to receive a luminescent light signal representing a property of each sample and to supply an electrical signal corresponding to said light signal, and measurement processing means connected to said detector means to convert the electrical signal supplied by the detector means into data providing a visual display of said property, wherein said measurement cell means is disposed in a liquid flow circuit for successive liquid samples, said flow circuit comprising: input means for successively receiving said samples; pump means, coupled between said input means and said measurement cell means, for pumping said samples through said flow circuit; and control means, connected to said pump means, for controlling said pump means, each time a sample is to be pumped, during at least such a time interval that each sample has a volume large enough both to flush from said cell means any residue from a previous analysed sample and also to fill said cell means. 
     
     
       2. An apparatus according to claim 1, which further comprises triggering means for triggering the light signal in said measurement cell means after it has been completely filled with a sample or when there is an overflow of a sample into overflow means. 
     
     
       3. An apparatus according to claim 2, wherein said triggering means comprises duct means extending into the measurement cell means and connected to valve means for controlling the addition to the cell means of a reaction substance able to trigger a reaction producing the light signal. 
     
     
       4. An apparatus according to claim 3, wherein said reaction is a bioluminescence reaction and said substance is an enzymatic solution. 
     
     
       5. An apparatus according to claim 4, wherein said duct means for the reaction substance terminates adjacent a recess in a wall of the cell means, and the flow circuit comprises duct opening means, located in the cell and also adjacent said recess, for delivering the liquid samples to be analysed into said cell means. 
     
     
       6. An apparatus according to claim 1, wherein said measurement cell means is in a capsule in the form of a plate in which are provided first cavity means to lodge the measurement cell means and second cavity means in liquid communication with the measurement cell means and with liquid-evacuation means for preventing any liquid flow back into the measurement cells means when the contents thereof are emptied by said pump means. 
     
     
       7. An apparatus according to claim 6, wherein said capsule is mounted on a casing containing said photometric detector means and said processing means. 
     
     
       8. An apparatus for photometrically analyzing a succession of distinct liquid samples, said apparatus comprising: a light-proof enclosure;   means, located in said light-proof enclosure, for defining therein a first cavity having a volume at most equal to the volume of each of a succession of distinct liquid samples to be analyzed;   photometric detector means mounted in said enclosure so as to be in light-communication with said cavity, said photometric detector means being able to generate a signal representative of luminescent light generated in the liquid samples;   input duct means connected to said cavity;   pumping means connected to said input duct means for successively supplying thereto and to said cavity said liquid samples to be analyzed;   control means, connected to said pump means, for controlling said pump means, each time a sample is to be pumped, during at least such a time interval that each sample has a volume large enough both to flush from the cavity any residue from a preceding sample and also to fill the cavity;   output duct means also connected to said cavity for respectively evacuating therefrom each sample just analyzed;   measurement processing means, connected to said photometric detector means, for converting said signal into data; and   display means, connected to said measurement processing means so as to be responsive to data for displaying a visual representation of said data.   
     
     
       9. An apparatus according to claim 8 further comprising means for triggering generation of said luminescent light in each liquid sample filling said cavity. 
     
     
       10. An apparatus according to claim 9 wherein said triggering means comprises auxiliary duct means communicating with said cavity, and metering means, connected to said auxiliary duct means, for introducing in said auxiliary duct means a metered quantity of a reaction substance able to trigger a reaction in each liquid sample in said cavity, said reaction generating said luminescent light. 
     
     
       11. An apparatus according to claim 10 wherein said means for defining said first cavity comprises a recess in fluid communication with said first cavity, said input duct means and said auxiliary duct means both opening into said recess. 
     
     
       12. An apparatus according to claim 8 further comprising means, located in said light-proof enclosure, for defining therein a second cavity, series-connected in said output duct means, to prevent any liquid flowback into said first cavity when the contents thereof are emptied by said pump means. 
     
     
       13. An apparatus according to claim 12, wherein said light-proof enclosure comprises plate, having recesses therein, and a casing against which said plate is mounted, said recesses being closed by said casing.